The present invention relates to embodiments of an adaptive cruise control system with speed based modes. Typical adaptive cruise control systems maintain the host vehicle in a time to target mode. If the target vehicle is moving slowly for long periods of time, such as through heavy traffic, the adaptive cruise control system allows the host vehicle to get closer and closer to the target vehicle as long as the time to the target vehicle is kept the same. Finally, if the target vehicle stops, the host vehicle in a time to target mode will brake aggressively. Additionally, the vehicle may release the brakes as soon as the target vehicle is no longer detected, causing the vehicle to jerk. Some drivers will disable the adaptive cruise control in slow traffic situations for this and other reasons. However, there is a desire for an adaptive cruise control system that is able to operate effectively regardless of the speed of the target vehicle.